Gastric Treatment/Diagnosis Device and Attachment Device and Method

ABSTRACT

A device, system and method for diagnosing and treating gastric disorders is provided. A functional device resides within the patient&#39;s stomach and is secured to the stomach wall by an attachment device. The functional device may be a sensor for sensing various parameters of the stomach or stomach environment, or may be a therapeutic delivery device. The functional device in one embodiment provides a device, system and method for gastric electrical stimulation where stimulating electrodes are secured to the wall of the stomach by the attachment device or otherwise. A preferred device includes: at least one stimulating electrode in electrical contact with the stomach wall; an electronics unit containing the electronic circuitry of the device; and an attachment mechanism for attaching the device to the stomach wall. The functional devices may be programmed to respond to sensed information or signals. An endoscopic delivery system delivers the functional device through the esophagus and into the stomach where it is attached the stomach wall. The endoscopic instruments attach or remove the attachment devices and functional devices from the stomach and may be used to assist in determining the optimal attachment location.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation of U.S. Ser. No. 10/295,128 filedNov. 14, 2002, which application is a divisional of U.S. Ser. No.09/847,884 filed May 1, 2001, now issued as U.S. Pat. No. 6,535,764; thefull disclosures of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

This invention relates to an implantable device, system and method forelectrically stimulating the stomach wall to effect gastric motility orotherwise treat gastrointestinal related disorders.

BACKGROUND OF THE INVENTION

Various organs of the gastrointestinal tract such as the stomach, smallintestine and colon contain cells that are believed to govern theorgans' periodic contractile behavior. In healthy humans, in certainregions of the organs, these cells generate and propagate rhythmicelectrical signals. In general, several types of electrical potentialactivity have been observed in the gastrointestinal tract. Consistentslow wave or pacesetter potentials have been observed and higherfrequency spike activity has been observed. The pacesetter potentialsare continuously propagating, relatively low frequency, cyclicdepolarizations of the smooth muscle cell lining. The higher frequencyspike bursts correspond to some extent with smooth muscle contractileactivity and peristalsis. In general, when the spike burst activityoccurs, it appears to be at a fixed time delay with respect to the slowwave potentials. It is believed that when the pacesetter potentials arecombined with a chemical or neural excitation of the cells that smoothmuscle contractile activity occurs. Also it is believed that thepacesetter potentials control and coordinate the frequency and directionof the contractions.

Electrical stimulation of the gastrointestinal tract has been proposedto treat motility related disorders and other gastrointestinal diseases.The electrical stimulation has been proposed in a number of forms, suchas, e.g., pacing, electrical contractile stimulation or otherstimulation, e.g., to treat nausea or obesity. Electrical pacing of thegastrointestinal tract is generally defined as a periodic electricalstimulation that captures and/or controls the frequency of thepacesetter potential or slow wave activity of the intestinal organ(including in a retrograde direction). Electrical contractilestimulation generally refers to stimulation that directly causes orresults in muscular contraction associated with the gastrointestinaltract.

In some disease states, dysrhythmias of the gastric pacesetterpotentials may be present. The result of the abnormal pacesetterpotentials may be gastric retention of food. Electrical stimulation ofgastric tissue has been proposed to induce peristalsis. Electricalstimulation has also been proposed to treat obesity by altering gastricmotility, or by stimulating neural pathways. For example, one treatmentmethod causes the stomach to retain food for a greater duration.Electrical stimulation has also been proposed to slow the gastricemptying to treat a disorder known as dumping syndrome where the stomachempties at an abnormally high rate into the small intestine causingvarious gastrointestinal disorders. In particular, electrical pacing ofgastric pacesetter potentials has been proposed to induce regularrhythms for the pacesetter potentials with the intent of inducingregular or controlled gastric contractions.

Within the stomach, at least one pacemaker region has been identifiednear the interface of the fundus and the corpus along the greatercurvature. This region has been one target for gastric pacing.Peristalsis controlled by this region is believed to serve to mix andbreak down food and propel small particles through the pylorus into theduodenum. It is believed that gastric emptying of liquids is alsocontrolled by the fundus. This region is believed to create withcharacteristic contractions, a pressure gradient between the funduspylorus and duodenum that relates to the rate of gastric emptying.

An early attempt at a gastric stimulation device included an electrodeat the end of a nasogastric tube or catheter. The nasogastric tube waspassed into the stomach transnasally. Electrical stimulation was appliedusing an external stimulator unit through the electrode on the end ofthe tube. The return electrode was placed on the abdomen. This devicerequired a transnasal procedure whenever stimulation was required.

Other devices used to pace the stomach have generally been implanted byaccessing the outside of the stomach through an opening in the abdomen,either through open surgery or laparoscopic surgery. Electrodes havebeen attached to the stomach wall with attached leads extending throughthe abdomen.

These procedures involve implanting a pacemaker device in a subcutaneousor sub-muscular pocket. The devices are anchored into the subcutaneousor sub-muscular pocket initially by a suture anchor and eventually byfibrous tissue ingrowth around the unit. The pacemaker device housing istypically constructed of a titanium or stainless steel material withconnectors molded into an epoxy header. The devices are thin in onedimension so that they are less visible when implanted directly underthe skin or muscle layer. Therefore, in order to accommodate thenecessary battery capacity, the devices are widely shaped, e.g. round orkidney shaped the other two dimensions. The leads extend from the unit'sepoxy header to a stimulation site remote from the pacemaker unit.

A gastrointestinal pacemaker having phased multi-point stimulation hasbeen proposed with electrodes placed in multiple points around the GItract including on the inner or outer surface of the stomach. Asdescribed, the device could be preprogrammed or include an implantablepacemaker detachably coupled to the multiple electrodes in their variouslocations, and including an electronic controller that may be programmedby using an external programmer to set stimulation parameters. Theimplantable pacemaker is located remote from the stimulation sites.

Some gastric stimulation procedures have proposed electrical stimulationin response to sensing electrical pulses within the stomach within aparticular range. Additionally, a device has been proposed to senseelectrical parameters to determine the fullness of an organ and theabsence of muscular contraction, and to deliver electrical muscularcontraction stimulation to the organ in response.

In general, the currently proposed gastric electrical stimulationprocedures are relatively invasive and require accessing the stomachthrough the abdomen, e.g., in an open or laparascopic procedures. Theunits have relatively wide dimensions in one plane. Accordingly, itwould be desirable to provide a less invasive procedure and device forelectrically stimulating the stomach.

A machine that places a nylon tag has been proposed for attaching a“payload” to the inner wall of a stomach. The machine places the tagthrough the stomach wall and back into the stomach in a manner thatcauses folding and may cause tissue damage when the smooth muscle of thestomach wall contracts. It would be therefore be desirable to provide anattachment device for attaching a device within the stomach wall thatminimizes device pull out forces, and that minimizes tissue damage whenthe smooth muscle of the stomach contracts, especially in electricallystimulating the smooth muscle of the stomach.

SUMMARY OF THE INVENTION

The present invention provides a device, system and method fordiagnosing and treating gastric disorders. The present invention furtherprovides a device, system and method for gastric electrical stimulation.Electrical stimulation is generally defined herein to mean anyapplication of an electrical signal or of an electromagnetic field totissue of the stomach for a therapeutic purpose. In one variation, thedevice is designed to facilitate or expedite mixing or breaking down offood matter or liquids in the stomach. In another variation, the deviceis designed to control, facilitate or expedite movement of food matteror liquids through the stomach and into the small intestine. In anothervariation, the device is designed to stimulate the stomach to delaypassage of food from the stomach and into the small intestine. Otherstimulation effects are also contemplated, including but not limited tousing stimulation to treat nausea, obesity or pain symptoms. Thestimulation may affect the smooth muscle contractions and/or nervesassociated with the stomach.

The stimulating (or diagnostic) device of the present invention resideswithin the patient's stomach. A preferred device includes: at least onestimulating electrode in electrical contact with the stomach wall; anelectronics unit containing the electronic circuitry of the device; andan attachment mechanism for attaching the device to the stomach wall.One or more stimulating electrodes may be secured to the wall of thestomach by the attachment device. One or more stimulating electrodes mayalso be located on the electronics unit. In a preferred embodiment, atleast one stimulating electrode is embedded in the wall of the stomach.Preferably the stimulation is provided through at least one pair ofbipolar electrodes. Alternatively a remote return electrode may beprovided in a monopolar device.

The attachment device may be either integrally formed with theelectronics unit or removably attachable to the electronics unit. Theattachment device and electronics unit may be deployed in two steps:first by identifying a site for attachment and attaching the anchor andsecond by attaching the electronics unit.

The electronics unit may be removable from the attachment device and ordeployed electrodes so that the electronics unit may be replaced aftertime. The stimulating electrodes may be coupled to the attachment deviceand/or the electronics unit. The attachment device may include, e.g., amechanical means such as a screw, suture, staple, clip or other anchor.The attachment device may include a release mechanism for easyendoscopic removal of the stimulating device from the stomach. In apreferred embodiment, the attachment device serves at least twofunctions: to hold the device in place as well as providing thestimulation or sensing. Thus, the preferred stimulation device is bothmechanically and electrically coupled to the stomach. Another preferredembodiment may include a stimulation device secured to the stomach withflexible leads attached to the preferred stimulation site.

The stimulation device is constructed of size and shape such that it canbe deployed through the mouth and esophagus with the aid of anendoscope. As such, the electronics unit is preferably of a generallycylindrical shape. The device components are constructed of materialsthat allow it to withstand and function in the highly acidic environmentof the stomach for two or more years. (The pH in the stomach may be, attimes, as low as 1.0). Such materials are relatively inert to theenvironment. An example of such materials are: suitable inert polymers,for example, materials from the Polyolefin family like HDPE (highdensity polyethylene), LLDPE (linear low density polyethylene), andUHMWPE (ultra high molecular weight polyethylene); fluoropolymermaterials like PTFE™ (poly tetrafluoroethylene), FEP™ (fluorinatedethylene propylene) and others; polymethylpentene, and polysulphons;some elastomers such as thermoplastic polyurethanes and C-Flex typeblock copolymers that are stable in acidic environments. The electrodesare preferably made of corrosion resistant metals such as, e.g.Platinum, Gold, Tantalum, Titanium and corrosion resistant alloys or oneor more of these metals. The electronics unit or shell may alternativelybe constructed of one or more of these metals or alloys. Electrodes arepreferably coupled to the electronic circuitry through sealed electricalcontacts or through leads extending into the housing through moldedcorrosion resistant materials such as those described above.

A preferred system of the present invention includes an endoscopicdelivery system for delivering the stimulator through the esophagus andinto the stomach where it is attached the stomach wall. One embodimentof the system includes a flexible endoscope or endoscopic instrument,for locating a preferred site in the stomach for device attachment. Inone embodiment, the endoscope or endoscopic instrument compriseselectrodes that may be placed on the inside of the stomach wall tomeasure electrical activity or impedance, or to deliver test stimulationpulsed to identify optimal stimulation parameters or locations. Theendoscope also provides one or more conduits through which tools forattaching the device are inserted. In one variation of the system anendoscope is used to implant a stimulating device having an anchor and amain body that is attached in situ to the attachment device or anchor.Preferably the anchor attaches the electrode of the device to thestomach wall and the main body includes the device electronics forproviding the electrical stimulation through the electrodes.Alternatively the electrodes may be attached to the stomach wallseparately from the anchor. The system includes an endoscopic instrumentor instruments for first attaching the anchor and then coupling the mainbody or electronics unit to the anchor. The device and delivery systemin a preferred embodiment includes a release mechanism in the stimulatorunit so that it may be removably attached to an anchor or attachmentdevice within the stomach so that the stimulator unit may be exchangedif desired. A preferred embodiment of the endoscopic system of theinvention provides a device for engaging a release mechanism on theattachment device or on the stimulator unit for disengaging thestimulator from the attachment device or for disengaging the attachmentdevice from the stomach wall.

In addition to the device being capable of stimulating the stomach wall,the electrodes of the device may also be used for diagnostic purposes.For example, the electrodes may be used to sense and observe electricalactivity in the stomach wall. Such sensing may be used over time toidentify patterns, diagnose diseases and evaluate effectiveness ofvarious treatment protocols. For example irregular or lack of EMGactivity may be sensed. Stimulation may be provided in response tosensed EMG activity or lack of activity.

In one variation, sensors can be included in the device or separatelyfor sensing various parameters of the stomach. The sensors may bemounted on the electronics unit, an attachment mechanism, or by othermeans, for example, in an independently attached device for exampleattached with an anchor. The stimulation device may include a mechanicalsensor that senses, for example, stomach wall contractions. As thestomach contracts, the stomach wall typically becomes thicker. In apreferred embodiment a device implanted in the stomach wall includes astrain gauge that is able to sense change in stomach wall thickness.Alternatively, electrical sensors may detect changes in impedance due tochanges in wall thickness from smooth muscle contractions. Otherexamples of such sensors may include, for example, pH sensors, impedancesensors, pressure sensors and temperature measuring devices such as athermocouple.

The stimulation device may be programmed to deliver stimulation inresponse to sensing electrical parameters or other sensed parameters.For example, a pH sensor may be used to determine when food has beeningested. When the pH changes in a manner, indicating food ingestion,the stimulation device may be instructed to deliver stimulation pulsesto stimulate gastric motility. The device may also be user controlled,where the recipient of the device is able to externally activate thedevice, for example by using an external unit which delivers a controlsignal via telemetry. A temperature sensor may be used, for example, todetermine when food has been ingested, by a change in temperature. Thedevice may begin stimulating the stomach upon detecting sudden change intemperature. Pressure sensors may be used to sense motility patterns,e.g. presence, strength or frequency of contractions. Mean pressureshifts may be observed to identify fundal contractility. The stimulationdevice may also use sensed parameters to program or reprogram the devicestimulation program. For example, measuring impedance changes through acircuit coupled to the electrodes (e.g., delivering a constant currentor voltage across the electrodes to determine impedance) or determiningthe contractile behavior of the stomach using a strain gauge, inresponse to stimulation pulses, the effectiveness of the stimulationpulses may be monitored and adjusted to provide optimal response. Thestimulation program may also include an automatic adjustment in responseto changes in pressure measurement.

Other diagnostic or treatment devices may be attached to the inside ofthe stomach wall, for example using a separate or integrally formedanchoring device. Preferably such devices are introduced and attached tothe stomach wall endoscopically. Such devices may include, for example,drug delivery devices, a gastric balloon, sensing or diagnostic devices.In one embodiment when excessive acid concentration is sensed using a pHsensor, a device is triggered to release an antacid drug, e.g., using adrug delivery pump.

The present invention also provides an attachment device for attaching afunctional device to the stomach wall. The functional device may be asensor for sensing various parameters of the stomach or stomachenvironment, or may be a therapeutic delivery device. The devices may beattached to the attachment device in a separate housing or may beintegral with the attachment device. The functional devices may bepowered by a battery included with the device or the functional devicesmay be inductively powered. In a preferred embodiment, the attachmentdevice is attached such that the device does not substantially constrainthe stomach in the plane of smooth muscle contractions and to minimizestresses in the tissue, to reduce the potential for tissue damage ordevice dislodgement. Preferably the attachment device attaches in amanner that avoids folding of the stomach wall. In one preferredembodiment, the attachment device is attached by piercing at least aportion of the stomach wall at a single point of penetration into thestomach wall. Also, in one embodiment the attachment device pierces thestomach wall in a direction perpendicular to the natural orientation ofthe stomach wall. Further, in a preferred embodiment, the attachmentdevice extends through the stomach wall with a backing mechanism locatedexternal to the stomach wall. Preferably such backing mechanism isrelatively atraumatic to the stomach outer wall and surrounding tissueand has a relatively high surface area in relation to the width of theattachment device or puncture hole. Another preferred embodimentprovides an adjustable bumper holding the anchor to the inside of thestomach wall. Such bumper is also preferably designed to have arelatively high surface area and to be relatively atraumatic to thestomach wall. Another preferred embodiment provides an attachment devicewith a quick release mechanism that enables relatively easy endoscopicremoval of the attachment device from the stomach.

Preferred embodiments of various aspects of the invention are describedin the following detailed description.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial cross sectional view of a system of a firstembodiment of the present invention in use in placing an electricstimulator in a patient's stomach.

FIG. 2 is a partial cross section view, illustrating placement of anovertube in the first embodiment of the system of the present invention.

FIG. 3 is a partial cross sectional view of the placement of an anchorin the stomach in the first embodiment of the system of the presentinvention.

FIGS. 4-6 are detailed partial cross sectional views illustrating theplacement of the anchor in the first embodiment.

FIG. 7 is a side partial cross sectional view of the proximal end of anendoscope of the inventive system.

FIG. 8 is a side view of a distal end of the endoscope of the inventivesystem.

FIG. 9 is distal end view of the endoscope of FIGS. 7 and 8.

FIG. 10 illustrates a partial cut away side elevational view of ananchor of the first embodiment initially placed in the stomach wall.

FIG. 11 illustrates a partial cut away side elevational view of a fully20 deployed anchor of FIG. 10.

FIG. 12 illustrates a side elevational view of the main body of thestimulator of the first embodiment of the present invention.

FIG. 13 illustrates a side elevational view of the main body and anchorof the stimulator where a tether coupled to the anchor is threadedthrough an opening in the main body to guide the main body to theanchor.

FIG. 14 illustrates a partial cut away side elevational view of thestimulator of the first embodiment of the present invention attached tothe stomach wall.

FIGS. 15-17 illustrate respectively the main body of the firstembodiment of the stimulator as it is placed through the esophagus, intothe stomach and connected with the anchor.

FIG. 18 illustrates a side cross sectional view of the deployed anchorof FIG. 11.

FIG. 19 illustrates a side cross sectional view of the main bodyillustrated in FIG. 12.

FIG. 19A illustrates an enlarged view of the latch mechanism of the mainbody portion shown in FIG. 19 with the latch in a closed position.

FIG. 20 illustrates an end cross sectional view of the main bodyillustrated in FIG. 12 with a quick connect in an open, unlockedposition.

FIG. 20A illustrates an enlarged view of the latch mechanism of the mainbody portion shown in FIG. 20 with the latch in an open position.

FIG. 21 illustrates an end cross sectional view of the main bodyillustrated in FIG. 12 with a quick connect in a closed, lockedposition.

FIG. 22 illustrates a side cross sectional view of the main body andanchor of the first embodiment locked together.

FIG. 23 illustrates a side elevational view of the anchor and main bodyof a second embodiment of the stimulator of the present invention.

FIG. 24 illustrates a side elevational view of the embodiment of FIG. 23with the anchor and main body attached.

FIG. 25 illustrates a schematic diagram of the circuit of an electronicstimulator of the present invention.

FIG. 26 illustrates a schematic diagram of the circuit of a 20programmer/recorder of the present invention.

FIG. 27A illustrates a third embodiment of the present invention showingan alternative anchor as it is inserted through the stomach wall.

FIG. 27B illustrates the anchor of FIG. 27A anchored to the stomachwall.

FIG. 28A illustrates a fourth embodiment of the present inventionshowing an alternative stimulation device.

FIG. 28B illustrates an enlarged view of an anchor of the stimulationdevice of FIG. 28A.

FIGS. 29A and 29B illustrate an alternative endoscopic instrument for 30placing an attachment device through a stomach wall.

FIGS. 30A and 30B illustrate a fifth embodiment of present invention inwhich an anchor is placed using the instruments of FIGS. 29A and 29B.

FIG. 31A illustrates a sixth embodiment of the present inventionincluding an anchor and stimulator.

FIG. 31B illustrates the anchor and stimulator of FIG. 31B attachedwithin the stomach.

FIG. 32 illustrates a seventh embodiment of the present inventionincluding a screw in attachment device.

FIGS. 33A and 33B illustrate an eight embodiment of the presentinvention including an anchor with a clip on attachment device.

FIGS. 34A and 34B illustrate a ninth embodiment of the present inventionincluding an inductively powered stimulation device.

FIGS. 35A and 35B illustrate a tenth embodiment of the present inventionincluding an endoscopic tool for mapping electrical activity in thestomach.

FIGS. 36A and 36B illustrate exemplary stimulation waveforms.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 10-14 and 18-22, a stimulator 10 of a firstembodiment is illustrated. The stimulator 10 comprises an anchor 123 anda main body portion 20. The anchor 123 comprises an elongate member 124having and expandable distal end 125 and a stimulating electrode 126 inthe form of a ring of a corrosion resistant metal conductor such asPlatinum, Gold, Tantalum, Titanium or suitable alloys thereof, extendingaround the elongate member 124 just proximal of the expandable end 125.The anchor 123 may be constructed of a radiopaque material.Alternatively, the anchor 123 may include radiopaque markers located onthe device so that the location and orientation of the device may beidentified, particularly after it has been placed. At least a portion ofthe anchor 123 is preferably coated with an antibiotic material, such asgentamicin sulphate or a silver/silver salts coating, particularly inlocations that it will extend through or come in contact with thestomach wall. A notch 127 extending around the elongate member 124 islocated proximally of the stimulating electrode 126, for connecting theanchor 123 to the main body portion 20, containing the stimulatorelectronic circuitry 25. An electrical contact member 128 comprising acorrosion resistant metal ring extends circumferentially around theelongate member 124 proximal of the notch 127. The electrode 126 and thecontact 128 are electrically coupled through a wire 129 or otherconductor extending through the elongate member 124. The proximal end ofthe anchor 123 has an opening 130. A tether 131 is secured to theopening 130. The tether 131 is used to guide the main body portion 20into place. The tether 131 is also used to pull on the anchor 123 whilethe main body portion is pushed into place both to provide a guide andto hold the anchor 123 in place.

A strain gauge 121 is located on the elongate member 124 of the anchor123. The strain gauge 121 is coupled through conductors 121 a and 121 bto electrical contacts 128 a, 128 b respectively. Electrical contacts128 a and 128 b are constructed and sealed when coupled to the main body20, in a manner similar to contact 128.

The main body portion 20 comprises a sealed housing 21 includingelectronic circuitry 25. The electronic circuitry 25 provides sensing,stimulating electronic pulses through the electrodes to the stomachwall, and telemetry communication with an external unit such as areader, recorder or controller. The housing 21 includes an outer shellhaving a distal face 26 for interfacing with the stomach wall. The mainbody 20 also includes a radiopaque marker 31, preferably a radiopaquestimulator serial number (e.g., sprayed onto a location in the housing21) so that the device and its location may be identified. The outershell is constructed of an acid corrosion resistant material such as asuitable inert polymer, for example, materials from the Polyolefinfamily like HDPE (high density polyethylene), LLDPE (linear low densitypolyethylene), and UHMWPE (ultra high molecular weight polyethylene);fluoropolymer materials like PTFE™ (poly tetrafluoroethylene), FEP™(fluorinated ethylene propylene) and others; polymethylpentene, andpolysulphons; some elastomers such as thermoplastic polyurethanes andC-Flex type block copolymers that are stable in acidic environments.Additionally the outer shell may be constructed of an acid corrosionresistant metal such as Platinum, Gold, Tantalum, Titanium, or suitablealloys thereof. The distal face 26 is preferably coated with anantibiotic material, such as gentamicin or silver/silver salts coating.The main body 20 further comprises an electrode 32 located on the distalface. The electrode 32 is constructed of an acid corrosion resistantmaterial such as Platinum, Gold, Tantalum, Titanium, or any suitablealloys thereof.

The main body portion 20 further comprises a channel 23 through whichthe tether 131 is threaded for alignment with the anchor 123 (FIG. 13)and for receiving the elongate member 124 of the anchor 123 (FIGS. 14and 22). A second channel 23 a extends parallel to the channel 23 froman opening in the proximal side of the main body 20 and ending withinthe main body 20. The second channel 23 a is for receiving aconnect/release tool 38 described in more detail below.

The channel 23 includes an opening 24 in the distal face 26 of the bodyportion 20 as well as an opening 22 a in the proximal side 22 of themain body 20. The walls of the channel 23 include a plurality of acidresistant elastomeric seals 27 formed of a material such as, forexample, polyurethanes, rubbers or C-Flex type block copolymers. Inbetween the seals 27 is a flexible electrical contact 28 for contactingthe electrical contact 128 of the anchor 123 and a latch 29 for engagingthe notch 127 of the anchor 123. Thus, the electrical contact 28 will belocated in a sealed area of the channel 23, between seals 27, protectingit from the highly acidic environment of the stomach. The seals 27 alsoact as electrical insulators that prevent unintended current pathwaysbetween the electrical contact 28 and the electrode 32. The electricalcontact 28 is coupled to the electronic circuitry 25 of the main bodyportion 20 through a conductor 30 extending from the circuitry 25through the housing 21 to the contact 28. The second stimulatingelectrode 32 located on the distal face 26 of the main body 20 iscoupled to the electronic circuitry 25 by way of a conductor 33. As analternative to being coupled to the electronic circuitry through asealed contact, the electrode 126 may be constructed in a manner similarto electrode 32 using a corrosion resistant material that is directlycoupled to the electronic circuitry (for example, where the anchor isintegrally formed with the stimulator 10 or where the electrode 26 islocated on the housing).

As illustrated in FIG. 22, when the main body portion 20 and the anchor123 are connected, the elongate member 124 of the anchor 123 extendsinto the channel 23 so that the notch 127 and the electrical contact 128are located between seals 27. The electrical contacts 128, 128 a, and128 b are in contact with flexible electrical contacts 28, 28 a, and 28b respectively, and the latch 29 is located within the notch 127 so thatthe elongate member 124 of the anchor 123 is fixed within the main bodyportion 20.

FIGS. 19-21 show the latch mechanism 29 in the main body 20 that is usedto connect the main body 20 to the anchor 123. The latch 29 is locatedwithin a closed channel 34 in the main body 20 that is orientedperpendicular to the channels 23 and 23 a. A spring member 36 is locatedat the end 35 of the closed channel 34 between the end 35 and the latch29. The spring 36 biases the latch 29 in a closed position asillustrated in FIG. 20 and described below. The latch 29 comprises aconnecting end 29 a that extends into the channel 23 when the latch 29is in its closed position. The latch 29 further comprises an opening 29b formed in part by a cam surface 29 c ending in tip 29 d. When thelatch 29 is in an open position (FIG. 19), the spring 36 is compressedand the cam surface 29 a and the tip 29 d are recessed into the closedchannel 34. When the spring 36 is released, the latch 29 moves into theclosed position where the cam surface 29 a extends into the channel 23and the cam surface 29 c and tip 29 d extend into the channel 23 a.

In use, the latch 29 tends toward the closed position. In order toconnect the anchor 123 with the main body 20, a connecting tool 38 isinserted into the channel 23 a and the tool 38 engages the cam surface29 c to move the latch 29 into the open position. Channel 23 a includesan elastomeric, self-sealing plug 23 b with a slit for receiving theconnecting tool 38. The plug 23 b seals the opening in the channel 23 afrom external fluids, etc. The tool 38 includes a notch 39 in its distalend. The tool 38 may be locked into position in the channel 23 a byrotating the tool so that the tip 29 d of the cam surface 29 c engagesthe notch 39. This prevents removal of the tool 38 from the channel 23a. Thus the tool 38 may be temporarily locked in the channel 23 a withthe latch 29 in an open position for insertion of the anchor 123 intothe channel 23. The tool 38 may be released when the anchor 123 is inplace, by rotating the tool so that the tip 29 d of the latch 29 nolonger engages the notch 39 in the tool 38. When connected, the elongatemember 124 of the anchor 123 is located in the channel 23 and the latchconnector 29 a extends into the notch 137 in the elongate member 124,thereby connecting the anchor 123 and the main body portion 20.Alternatively, the main body portion 20 may be connected to the anchor123 without the use of such a tool. In this case, the anchor 123 causesthe latch to retract as the anchor 123 is inserted until the connectingend 29 a of the spring-loaded latch 29 locks into place in the notch137.

The tool 38 may be used in a similar manner as described above, toremove the main body 20 from the anchor 123, for example to replace themain body 20 or remove the stimulator 10. The tool 38 is preferably adevice that may be inserted through a lumen in an endoscope. In suchcase, the tool 38 may first be placed through the endoscope and attachedto the stimulator distal of the endoscope's distal end. This wouldparticularly be the case where the stimulator is larger than thechannels in the endoscope. Other endoscopic tools may be used to deployor remove the stimulator 10 or main body 20. For example, a graspingtool may be used manipulate the device where the grasping tool has anactuator handle extending out of the proximal end of the endoscope. Alsoa magnetic tool may be used to engage and manipulate the stimulatorduring insertion or removal. A magnetic docking system may be used aswell, to locate or orient the main body 20 in an aligned position withrespect to the anchor 123. The main body, anchor insertion tool orendoscope may have magnets that provide for aligned connection betweenthe main body 20 and anchor 123.

FIGS. 1-9 and 15-17 illustrate an endoscope of the system of the presentinvention and the placement of the electrical stimulator 10 using theendoscope and associated instruments. FIG. 1 illustrates a flexibleendoscope 110 such as, for example, of a type that used bygastroenterologists in treating the upper gastrointestinal tract. Theendoscope 110 is used to locale an attachment site in the stomach 100and attach the stimulator device 10 to the stomach wall of a patient.The flexible endoscope is of the type that is typically used bygastroenterologists in accessing the esophagus or stomach. The endoscopeallows the physician to visualize while performing procedures on theupper gastrointestinal tract. The flexible endoscope may be, forexample, a flexible fiber optic endoscope utilizing optic fibers forimaging or a video endoscope that uses a CCD (charge coupled device) toprovide video images. Such endoscopes typically include a fiber opticlight guide and a complex objective lens at the distal end to focus theimage.

As illustrated in FIGS. 7-9, the endoscope comprises an elongate tubehaving a proximal handle portion 106 and a distal portion 115. Theendoscope includes an aspiration channel 112 and irrigation/air channel113. A fiber optic light source 93 for illuminating the stomach siteextends through a fiber optic channel. A video lens 94 is located at thedistal end of the endoscope, for receiving and focusing the image thatis transmitted back through a channel in the endoscope 110.Corresponding light source input 95, video output 96, irrigation port97, aspiration port 98 and auxiliary port 99, are located on theproximal handle portion 106. Knobs 107 and 108 are coupled at theproximal handle 106 for left/right and up/down steering mechanisms,respectively, that are used to steer the distal portion of the endoscopein a manner that is generally known to one of ordinary skill in the art.The endoscope 110 further includes an auxiliary channel 114 extendingthrough the endoscope 110 and providing an opening through whichsurgical instruments may extend to reach the site 105. An additionalauxiliary port may be provided for additional instruments oralternatively, the aspiration channel 112 may be used for additionaltools if not otherwise required in a procedure. The distal portion 115of the endoscope 110 includes an open distal tube 116, the end of whichis placed against the stomach wall at the site 105. The distal tube 116provides a space for stomach tissue to enter and be held in place when avacuum pressure is applied.

During the procedure the patient is given a numbing agent that helps toprevent gagging. As shown in FIG. 2 a protective overtube 111 with theendoscope 110 is passed through the mouth 101, pharynx 102, into theesophagus 103 and opening into the stomach 100. The overtube 111 is usedto protect the esophagus, which may become irritated with repeatedinsertion and removal of instruments. The overtube 111 also helpsprevent instruments and devices from inadvertently dropping into thetrachea. In addition, the overtube 111 serves to protect the tools fromthe bacteria in the mouth and esophagus so that such bacteria are notpassed on to the stomach wall. As illustrated in FIG. 9, the overtube111 a may also include additional channels 111 a and 111 b for insertingadditional instruments.

Preferably the instruments inserted into the patient's stomach arecoated with an antibacterial material, in particular, the instrumentsthat are used to pierce or otherwise come in contact with the stomachwall. As illustrated in FIG. 3, the endoscope 110 is extended distallyout of the overtube 111 and is used to locate a site 105 on the stomach100 for attaching the stimulator 10. Additionally or alternatively, anendoscope or a tool inserted through the esophagus may be used to detectintrinsic gastric electrical activity to help pinpoint the optimal sitefor a stimulator and/or electrode attachment to the stomach wall (Seefor example, FIGS. 35A and 35B and the corresponding descriptionherein). In such a case sensing electrodes are coupled to the distal endof the endoscope or tool, with conductors extend out of the endoscope orpatient's esophagus to a unit having a controller for receiving sensedelectrical activity and identifying a surgical site for stimulatorattachment.

As shown in FIGS. 4-6 an introducer 117 is inserted through theauxiliary channel 114. The introducer 117 comprises an outer cannula118, a dilator 119 extending through the cannula 118, and a needle 120extending through the dilator 119. Each of the cannula, 118, dilator 119and needle 120 are separately actuable at the proximal end in a mannerthat would be apparent to one of ordinary skill in the art, for example,in a manner similar to such devices utilized in catheter introducersets. After the open distal tube 116 is located at a site 105 in thestomach 100, a vacuum pressure is applied through the aspiration channel112 to engage, stabilize and hold the tissue at the site 105. Asillustrated in FIG. 4, the needle 120 is advanced distally through thetissue of the stomach wall. As illustrated in FIG. 5, the dilator 119 isthen advanced over the needle 120 through the stomach wall. The needle120 is then retracted proximally out of the dilator 119 and is removedfrom the endoscope 110. The cannula 118 is advanced over the dilator 119and the dilator 119 is removed proximally from the endoscope 110.

As illustrated in FIG. 6, with the cannula 118 through the stomach wall,the anchor 123 may be placed into the cannula 118 from the proximal endof the endoscope. Using a push tube 122 having a diameter that is smallenough to fit within the cannula 118, placed proximally of the anchor123, the anchor 123 is distally advanced through the cannula 118 locatedwithin the stomach wall (FIG. 10).

The push tube 122 pushes the anchor 123 through the cannula 118 untilthe expandable distal end 125 extends out of the stomach wall in theperitoneal cavity. (FIG. 11) Before insertion, a tether 131 is securedto the opening 130 and extends through the push tube 122 out of theproximal end of the endoscope 110. The expandable distal end 125 isformed of an elastic or spring material that tends to spring open intoits expanded shape when the distal end 125 is no longer constrained bythe cannula 118. (FIG. 11). Once the anchor 123 is in place, the cannula118 is withdrawn from the endoscope 110 and the endoscope 110 may alsobe removed from the over tube 111 leaving the tether 131 in placeextending from the anchor 123 out of through the over tube 111 and outof the patient's mouth 101. The tether 131 is to be used to guide themain body 20 of the stomach to the anchor 123. The tether 131 maycomprise a thread or suture-like device or may be a thin flexible guidewire like device. The tether 131 may be tied or otherwise anchored tohole 130 in anchor 123 or it may be looped through hole 130 in anchor123 such that two strands lie parallel to each other in the overtube 111and pass out of the patient's mouth.

FIGS. 15-17 illustrate a preferred procedure for connecting the mainbody portion 20 of the stimulator 10 to the anchor 123 in place in thestomach wall. The main body 20 is threaded on to the tether 131 that isattached to the anchor 123 through the channel 23 in the main body 20.The tether 131 which extends through the over tube 111, guides thechannel 23 to the elongate member 124 of the anchor 123 for attachment.The threaded main body portion 20 is preferably placed within the overtube 111 with the endoscope 110 located proximal of the main bodyportion 20 within the overtube 111. The tether 131 is also preferablythreaded through the overtube 111, placed in parallel with the endoscope110 through the overtube 111 or one of its channels 111 a, 111 b. Thetether may be placed in a lumen extending through the endoscope 110.Tool 38 extends through the auxiliary channel 114 and is coupleddistally of the distal end 115 of the endoscope, to the main body 20through the channel 23 a. The endoscope 110 distal portion 115 alsoengages the main body portion 20 and provides a force to move the mainbody portion 20 through the over tube 111. (FIG. 15). The endoscope 110further provides visualization of the coupling process. The tool 38 andtether 131 together further locate the main body portion 20 with theanchor 123 as it extends through the stomach 100 to the site 105. (FIG.16). Finally, the tool 38 provides additional force to attach the mainbody portion to the anchor 123 (FIG. 17). The tool 38 is then removedfrom the channel 23 a in the main body 20 and out of the endoscope'sproximal end. Alternatively the main body 20 may be placed in position,coupled to the anchor 123 by using the tether 131 and the distal portion115 of the endoscope to guide the main body 20 into place. (See e.g.,FIGS. 15-17). In an alternative embodiment, a magnetic docking system isused wherein the distal end 115 of the endoscope 110, main body 20,and/or anchor 123 includes a magnet and/or corresponding metal used toalign and position the anchor 123 and main body 20 with respect to eachother.

After the main body portion 20 has successfully been coupled to theanchor 123, an endoscopic scissor or other cutting device may beprovided through the auxiliary channel 114 in the endoscope 110 to cutthe tether 131. As illustrated in FIG. 14, when the stimulator isattached to the stomach wall, the stimulating electrode 32 is locatedwithin the tissue of the stomach wall, providing electrical contact.While the second stimulating electrode 32 on the distal face 26interfacing with the stomach 100, is in electrical contact with theinner surface 100 b of the stomach wall.

FIGS. 23 and 24 illustrate a second embodiment of the stimulator of thepresent invention. Stimulator 210 comprises a main body portion 220 andan anchor 223. The anchor 223 comprises an elongate proximal member 225.The elongate proximal member 225 includes a tether opening 235 in theproximal end, electrical contacts 228, 238, and a notch 227 forconnecting the main body portion 220 to the anchor 223. The distalportion 240 of the anchor 223 comprises two prongs 241, 242. Prongs 241,242 have expandable distal ends 243, 244 respectively that areconstructed in a similar manner as the expandable distal end 125described above with respect to the first preferred embodiment. Astimulating electrode 245 is located on prong 241 and an electricallyopposite second stimulating electrode 246 is located on prong 242.Stimulating electrode 245 and second stimulating electrode 246 arecoupled to electrical contacts 228 and 238 respectively by conductors229 and 239 extending through prongs 241, 242 respectively into theelongate proximal member 225. Prongs 241 and 242 are connected by aspacer 237.

Main body portion 220 includes a channel 215 with an opening 216 on thedistal face 226. The channel 215 and the opening 216 on the distal facehave shapes that allow them to respectively receive the elongateproximal member 225 and the spacer 237, thereby sealing the opening 216.The electrical contacts 228, 238 to the anchor 223 are coupled toelectrical contacts within the channel 215 of the main body portion 220in a manner similar to the coupling of contacts 128, 128 a and 128 b ofanchor 123 and contacts 28, 28 a, and 28 b of main body portion 20described with reference to the first embodiment herein. Also the notch227 engages a latch similar to the latch 29 described above. The notch227 and latch and the electrical contacts 228, 238 are isolated from theacidic environment of the stomach using seals such as the seals 27described above with respect to the first embodiment. Alternatively, theelectrodes 245, 246 may be constructed in a manner similar to electrode32 using a corrosion resistant material that is directly coupled to theelectronic circuitry (for example, where the anchor is integrally formedwith the stimulator or where one or more of the electrodes 245, 246 arelocated on the main body portion).

The anchor prongs 241, 242 may be deployed in a similar manner as anchor123 is deployed, using a dual needle introducer or, alternatively bydeploying each prong 241, 242 independently and later connecting theprongs 241, 242 with the spacer 237.

In use, once the stimulator (e.g., 10, 210, 310 or 380) is deployed,electrical stimulation is provided through electronic circuitry 25. Theelectronic circuitry 25 is capable of producing various types ofprogrammable waveforms. FIGS. 36A and 36B illustrate examples ofstimulation waveforms that may be used in stimulating the smooth musclelining of the intestinal tract. FIG. 36A illustrates a waveform designfor stimulating the intestinal tract at a pacing rate. In a preferredembodiment, the waveform 1 has a pulse amplitude of between 0.5 and 20milliamps, a pulse width of between 0.5 and 10 milliseconds, and afrequency of about between 1 and 5 pulses per minute. FIG. 36Billustrates an alternative waveform design for stimulating theintestinal tract. The waveform 2 utilizes bursts of pulses rather than asingle pulse with a burst repetition rate to be selected, preferably ofabout 3 cycles per minute. The duration of a burst in this example isabout 100 ms and an amplitude of about 10 mA. In this example, thefrequency of the burst pulses during a burst is between about 50 to 100Hz, and as is well known to those skilled in the art, there are manydifferent types of electrical stimulation programs and strategies whichcan be utilized for providing electrical stimulation parameters throughthe circuitry 25, the principal focus being providing electricallystimulating parameters for the stomach.

A preferred embodiment of the electronic circuitry 25 is illustrated inFIG. 25. The electronic circuitry 25 of the stimulator is located in themain housing. The circuitry 25 comprises, a microprocessor or controller40 for controlling the operations of the electronic circuitry 25, aninternal clock 41, and battery device 44 such as a pair of lithiumiodine batteries for powering the various components of the circuit 25.As such, the controller 40 and battery device 44 are coupled to each ofthe major components of the circuit as would be apparent to one ofordinary skill in the art. The controller 40 is coupled to stimulationdriver 42, which is coupled to stimulating electrodes (e.g., 126, 32 or245, 246) that are used to provide electrical stimulation in accordancewith programmed parameters.

The controller 40 is coupled to ROM 43, which contains the programinstructions for the controller 40 and any other permanently storedinformation that allows the microprocessor/controller 40 to operate. Thecontroller 40 addresses memory in ROM 43 through address bus 43 a andthe ROM 43 provides the stored program instruction to the controller 40via data bus 43 b. The controller 40 controls the telemetry coil 45,which communicates with an external control or programming device 60(FIG. 26), preferably via a modulated RF signal. Processor 40 is coupledto an oscillator 51 that provides an RF signal to be emitted from thetelemetry coil 45. The RF signal is preferably at about 500 kHz orhigher so that the signal is efficiently transmitted through tissue. Thecontroller 40 controls the oscillator 51 and provides data to bemodulated with the RF signal. For example, various sensed data such aspressure, pH, temperature, strain, impedance, electrical activity (EMG)etc., may be delivered through the telemetry coil 45.

The circuit 25 may also be coupled through A/D converters 46 a, 46 b, 46c, 46 d to one or more sensors 47 a (e.g., strain gauge), 47 b (e.g.,pressure), or electrodes 32, 126. Suitable types of these sensors aregenerally known in the art and may be located within, on, or external tothe housing 21 of the main body portion 20. Controller 40 is coupled toRAM 50 via an address bus 50 a for addressing a location in RAM 50 and abi-directional data bus 50 b for delivering information to and from RAMmemory 50. The RAM memory 50 includes event memory 48 that temporarilystores data recorded by sensors 47 a, 47 b, 32 and 126 and aprogrammable memory 49 which may be programmed, for example, by anexternal programmer 60, to provide treatment protocols, e.g. to specifyoperating modes such as waveform, frequency, etc. The strain gauge 47 ais coupled through A/D converter 46 a, which converts the representativeelectrical signal output by the strain gauge into a digital signal,which is delivered to the microprocessor/controller 40 and stored in theevent memory 48 in the RAM 50. The sensor 47 b is coupled through A/Dconverter 46 b, which converts the representative electrical signaloutput by the sensor 47 b into a digital signal, which is delivered tothe microprocessor/controller 40 and stored in the event memory 48 inthe RAM 50. The electrodes 32, 126 are coupled through A/D converters 46c and 46 d to the microprocessor 40. A/D converter 46 c converts theelectrical EMG signal sensed by the electrodes 32, 126 into a digitalsignal representative of the EMG electrical activity, which is deliveredto the microprocessor/controller 40 and stored in the event memory 48 inthe RAM 50. Also, the A/D converter 46 d converts the electrical signalsensed by the electrodes 32, 126 and provided through the impedancecircuit 53 described below, into a digital signal representative oftissue impedance, which is delivered to the microprocessor and stored inthe event memory 48 in the RAM 50. The data stored in the event memory48 may be sent intermittently as data bursts via the telemetry RF coil45, as opposed to continuously in order to save battery power.

The electrode 32, 126 outputs are used to provide electrical stimulationdelivered through the stimulation driver 42 to electrodes. Thestimulation modes and parameters can either be set using the externalprogrammer 60, or they may be set in response to sensory feedback. Thesame electrode outputs are used to sense impedance through impedancecircuit 53 and to sense electrical activity which is delivered throughdriver 56 c. The electrodes 32, 126 are coupled through couplingcapacitors 55 a and 55 b respectively, to output of electricalstimulation driver 42 and input of drivers 56 c, 56 d.

The impedance circuit 53 comprises a constant current source oscillator54 that oscillates at a frequency of 50-100 kHz, and a driver 56 dcoupled through A/D converter 46 d to the controller 40. The oscillator54 provides a constant current source through electrodes 32, 126resulting in a voltage across the electrodes 32, 126 that isrepresentative of impedance, in view of the constant current. Thevoltage is provided through driver 56 d and is converted by A/Dconverter 46 d to a digital signal representative of impedance. Driver56 d has a bandwidth that includes the 50 kHz frequency signal whilefiltering out the electrical stimulation signal that is delivered to theelectrodes 32, 126 through electrical stimulation driver 42, and the EMGsignal that is sensed by the electrodes 32, 126. Both of the outputs arefiltered out by driver 56 d. Driver 56 c which delivers the EMG signalto A/D converter 46 c, also has a bandwidth that filters out the 50-100kHz signal. Further, when a stimulation signal is being delivered, thecontroller 40 does not receive signals from A/D converters 46 c and 46d. Thus the EMG and impedance sensing functions and the stimulationdeliver functions are separated through the electronic circuitry 25,though using the same electrodes.

FIG. 26 illustrates the electronic circuitry 63 for external programmer60. The electronic circuitry 63 comprises: a microprocessor orcontroller 70 for controlling the operations of the electroniccircuitry, an internal clock 71, and a power source 74 such as batterydevice for powering the various components of the circuit 63. As such,the controller 70 and battery device 74 are coupled to each of the majorcomponents of the circuit as would be apparent to one of ordinary skillin the art. The controller 70 is coupled to a speaker 67 for thatprovides audible alerts and a display 66 such as a CRT to display datasuch as recorded data, sensed parameters treatment parameters and statusof device (e.g. position or battery charge status). The controller 70 iscoupled through a buffer 64 to external input device 65 that is used toprovide program parameter input, e.g. from a user, for a user to requestdata displayed in a desired format through display 66 or speaker 67, orto turn device on and off. The external programmer 60 is also providedwith an external data port 68 to interface with a computer and provide ameans for bi-directional communication of data or commands. The computermay provide programming or data to the controller/microprocessor 70. Auser may also interface with the computer to provide treatment protocolsor changes in protocols, etc. Also, a user may control the turning onand off of the stimulation program.

The controller 70 is coupled to ROM 73, which contains the programinstructions for the controller 70 and any other permanently storedinformation that allows the microprocessor/controller to operate. Thecontroller 70 addresses memory in ROM 73 through address bus 73 a andthe ROM 73 provides the stored program instruction to the controller 70via data bus 73 b. The controller 70 controls the telemetry coil 75,which communicates with stimulator electronics 25 (FIG. 25) through itstelemetry coil 45. Processor 70 is coupled to an oscillator 72 thatprovides an RF signal, preferably having a characteristic frequency of500 kHz or higher, to be emitted from the telemetry coil 75. Thecontroller 70 controls the oscillator 72 and provides data to bemodulated with the RF signal, for example, programming information,stimulation parameters, etc. The telemetry coil 75 also receivesinformation transmitted via RF signal from telemetry coil 45 on thestimulator 10 such as various sensed data, e.g., pressure, pH,impedance, electrical activity (EMG) etc. The received RF signal ispassed through A/D converter 76 and is transmitted to the controller 70.The data is delivered to the event memory 78 in RAM 77 by way of databus 77 b for temporary storage. The data may be retrieved from RAM 77 byaddressing the storage location via the address bus 77 a.

Event memory 78 temporarily stores data recorded by sensors 47 a-47 cand delivered via telemetry to the external programmer 60, until thedata is downloaded onto a computer using the external data port 68. TheRAM 77 also includes a programmable memory 79 which may be programmed,for example, to specify operating modes such as waveform, frequency, etcwhich programming is then telemetrically communicated to the stimulationdevice 10, 210. The modes and parameters can either be set using anexternal programmer 60 or set in response to sensory feedback.

FIGS. 27A and 27B illustrate a third embodiment of the present inventionshowing an anchor device for use with a stimulator or other functionaldevice of the present invention. The anchor 263 comprises an elongatebody 264, an expandable distal portion 265 having a sharp tip 270, abipolar electrode pair 266, 267, and a bumper 275 located on a proximalportion of the elongate body 264. The expandable distal portion 265comprises a flexible disk 271 for engaging the outer stomach wall. Thedisk 271 has an inner surface 271 a that interfaces with the outersurface 100 a of stomach wall 100 and may, for example be coated with anantibiotic material, such as gentamicin sulphate or a silver/silversalts coating such as a powder. The bipolar stimulating electrode paircomprises electrode 266 located on the elongate body 264 and a pluralityof electrodes 267 electrically opposite from electrode 266, located atthe end of the expandable distal portion 265. The electrodes may beseparately coupled to electrical contacts and may be individuallyselected to provide optimal stimulation pulses, for example, based oncontractile response when stimulation pulses are delivered to aparticular electrode or electrodes. Electrode 266 is ring extendingcircumferentially around the elongate body 264. Electrodes 267 arecircumferentially spaced from each other around the radial extremity 271b of the disk 271. As an alternative to a plurality of electrodes 267the electrode located on the disk may be a single ring electrode.Electrodes 266, 267 are electrically coupled to a main body portioncontaining electronic circuitry (not shown) that is attached in a mannersimilar to main body portion 20 described above. Conductors 268, 269electrically couple electrodes 266, 267 respectively to the electroniccircuitry of the main body portion.

The anchor 263 may be deployed without requiring an introducer such asdescribed above with reference to FIGS. 4-6. As illustrate in FIG. 27A,the sharp tip 270 is used to pierce the stomach wall 100. The flexibledisk 271 folds within recessed portion 265 a extending around the distalportion of the anchor 263 so that the disk 271 is flush with the outersurface of the elongate body 264 and forms a taper to the sharp tip 270.The tip 270 is preferably conically tapered so as to atraumaticallydilate the stomach wall as it is inserted and help insure a good sealformed by the elastic rebound of the stomach wall tissue around theelongate body 264.

Referring to FIG. 27B as the distal portion 265 of the anchor 263extends through the stomach wall, the expandable disk 271 opens. Theanchor 263 is retracted slightly so that the radial extremity of thedisk 271 engages the outer surface 100 a of the stomach wall 100,preventing proximal movement of the anchor 263. The electrodes 267 arein electrical contact with the outer surface 100 a of the stomach wall.The electrode 266 on the elongate body 264 is embedded within thestomach wall 100 and is in electrical contact with the tissue therein.The bumper 275 may be advanced distally so that is engages the innersurface 100 b and secures the anchor 263 in position, preventing distalmovement. Preferably the bumper 275 and the disk 271 lock the anchor inplace and may also further serve to help seal the opening formed in thestomach from the acidic internal stomach environment and the environmentexternal the stomach wall 100. The bumper 275 may be secured in positionby a ratchet mechanism or other means such as a frictional fit. The tip270 is constructed of a bioabsorbable material such a glucose basedabsorbable material or polyglycolic acid or polylactic acid, so that thesharp tip 270 readily dissolves and is absorbed by the body, preventingthe tip from injuring tissue external to the stomach.

FIGS. 28A and 28B illustrate a fourth embodiment of the presentinvention showing a stimulator. Stimulator 310 comprises an anchor 323,an electronics unit 320 and electrodes 326, 327 coupled by leads 328,329 respectively to the electronics unit 320. The stimulator 310 isattached to the inner surface 100 b of the stomach wall 100 by anchor323 which may be constructed or attached in a manner similar to anchors123, 223, or 263 described above, either with or without electrodes. Theelectrodes 326, 327 are anchored into the stomach wall 100 with anchors324, 325 respectively. Referring to FIG. 28B, an anchor 325 is showndeployed in the stomach wall 100. Lead 329 extends from the main bodyportion 320 through the stomach to the site 105 where stimulation isdesired. The anchor 325 is preferably constructed in a manner similar toanchor 263 with a bioabsorbable or resorbable tip and so that theelectrode 327 is embedded in the stomach wall 100. The ends of the leadsare molded into the housing corrosion resistant materials suitable forlong term use in the stomach. Adjustable sealing ring or bumper 321operates to prevent anchor 325 from moving out of the stomach and mayhelp to seal the opening in the stomach wall formed by the anchor fromthe acidic stomach environment and. Anchor 324 is deployed in a similarmanner with electrode 326 embedded in the stomach wall 100 at the site105 for stimulation. Preferably the stimulating electrodes 326, 327 arelocated at a distance from each other between 5 and 10 mm so that theelectrical stimulation is delivered efficiently to the area of interest.The electronic circuitry of the main body 20 delivers electricalstimulation in a manner similar to the stimulation device 10 describedabove.

Referring now to FIGS. 29A and 29B, an alternative instrument isillustrated for placing an anchor from the inner surface 100 b of thestomach wall 100 through to the outer surface 100 a of the stomach wall.The instrument 330 comprises a hollow piercing needle 331 having a lumen332 therethrough and a stomach piercing tapered distal end 333. A guidewire 334 extends through the lumen 332 in the needle 331. The needle 331is relatively stiff to allow it to pierce the stomach wall while theguide wire 334 is more flexible. As illustrated in FIG. 29A, the distalend 115 of the endoscope is located at a desired site on the inside 100b of the stomach wall 100. A vacuum pressure is applied to the wall tostabilize it and the needle 331 pierces the stomach wall through asingle point, preferably in a direction that is substantiallyperpendicular to the natural orientation of the stomach wall to preventfolding of the stomach wall and tearing forces during smooth musclecontraction, at the point of attachment. As illustrated in FIG. 29B, theneedle 331 is removed, leaving the guide wire 334 in place. Preferably,the instrument 330 is inserted through the auxiliary channel 114 in theendoscope or through a channel 111 a or 111 b in the over tube 111 andthen is located to the desired site using the endoscope 110 forvisualization.

Referring to FIGS. 30A and 30B, an anchor 340 is illustrated placed intothe stomach wall 100 over the guide wire 334. The anchor 340 includes anelongate member 341 that is to be placed through the stomach wall 100 ina direction substantially perpendicular to the stomach wall. The anchor340 has a distal portion 343 that is to at least partially extendthrough the stomach wall, and a proximal portion 342 having a threadedproximal end 342 a for engaging with a threaded end of an instrumentused to advance the anchor 340 into place. The anchor 340 includes aguide wire lumen 345 extending through the anchor 340 from the proximalportion 342 to the distal portion 343 with an opening in the proximalportion 342 and distal portion 343 for receiving the guide wire 334 ofthe insertion instrument 330. As shown in FIG. 30A, the anchor 340 isinserted over the guide wire 334 which guides the anchor 340 intoposition through the stomach wall 100. The guide wire lumen 345 at thedistal portion 343 of the anchor 340 is sealed with a self-sealing plug344 formed of an elastomer and having a slit along the plug 344 so thatthe guide wire 334 can open the plug 344 while the guide wire 334extends through the lumen 345.

An expandable member 348 is located on the distal portion 343 of theanchor 340. The expandable member 348 comprises a balloon formed ofeither a compliant or non-compliant material such as, e.g.,polyurethane, polyethylene or polyester bonded to the outer surface ofthe distal portion 343 of the anchor 340 and providing an inflationchamber 350. Accordingly, the balloon may be inflated to a predeterminedpressure (typically using a non-compliant material) or a predeterminedvolume (typically using a compliant material). An inflation lumen 351extends from an opening in the proximal portion 342 to an opening 349 inthe distal portion 343. The opening 349 in the inflation lumen 351 is influid communication with the inner chamber of the expandable member 348so that an inflation medium may be supplied through the inflation lumento inflate the expandable member 348. As illustrated in FIG. 30B, theanchor 340 is placed in the stomach wall and the expandable member 348is inflated by supplying the inflation chamber 350 with an inflationmedium. In a preferred embodiment, a curable elastomeric polymer is usedas an inflation medium, e.g., a two-part curable elastomeric polymermixed just prior to delivery through the inflation lumen 151. Thepolymer thus allows the balloon to conform to the outer stomach wall andsurrounding tissue to secure the anchor 340 to outer surface 100 a ofthe stomach wall. The balloon is preferably designed and the inflationmedium is selected to provide an inflated distal end that issufficiently firm to secure the anchor 340 in place while havingsufficient surface area and being malleable enough that the anchor issealed into place in a relatively atraumatic manner.

The anchor 340 further comprises ratchets 365 on the outer circumferenceof the elongate member 341 and a sealing bumper ring 366 having anopening 367 forming an inner circumferential wall with ratchet teeth 368for engaging the ratchets 365 on the elongate member 341. The bumperring 366 is moveable in a distal direction to sealingly secure theanchor 340 to the stomach wall and prevent distal movement of the anchor340. The bumper ring 366 preferably has sufficient surface area and isformed of an elastomer that spreads the load and minimizes friction orother trauma to the stomach wall.

The anchor 340 further comprises electrode lumens 346, 347 havingopenings 346 a, 347 a in the elongate member 341. Conductor members 352,353 extend through the electrode lumens 346, 347, respectively, andinclude flexible conductors insulated along their length. The flexibleconductor members 352, 353 are preferably constructed of an elastic orsuperelastic alloy with an insulative coating. Electrically oppositeelectrodes 356, 357 are located on distal portions 360, 361 of moveableflexible conductor members 352, 353 respectively. Exposed electricalcontacts 354, 355 are located on the proximal portions of the conductormembers 352, 353. The electrical contacts 354, 355 are in electricalcontact with contacts 362, 363 respectively that are electricallycoupled to contacts in a main body of a stimulator unit in a mannersimilar to the sealing electrical connection of main body 20 and anchor123 described herein. The adjustable electrodes 356, 357 are containedwithin the electrode lumens 346, 347 when the anchor 340 is initiallyplaced as illustrated in FIG. 30A. The adjustable electrodes 356, 357are deployed within the stomach wall 100 by advancing the conductorsmembers 352, 353 distally through the electrode lumens 346, 347 wherethe openings 346 a, 347 a are configured to direct the electrodes 356,357 laterally from each other and within the stomach wall as illustratedin FIG. 30B. The electrodes 356, 357 are moved with respect to oneanother into a selectable optimal deployment position with an optimaldistance between the electrodes 356, 357.

An endoscopic instrument 370 is used to place the anchor 340, inflatethe expandable member 348 and deploy the electrodes 356, 357. Theinstrument 370 is preferably used through the overtube 111, an opening111 a or 111 b in the overtube 111 and/or through an instrument channel114 in the endoscope 110 (while the procedure is visualized through theendoscope 110.) The instrument 370 includes an inflation tube 373removably attached to the inflation lumen 351 of the anchor 340. Theinflation tube 373 forms a continuous conduit with the inflation lumen351 a conduit through which an inflation medium is supplied to inflatethe expandable member 348. A push tube 371 comprises a threaded end 371a that engages the proximal end 342 a of the anchor 340. The push tube371 is used to advance the anchor 340 over the guide wire 334. An innertube 372 includes prongs 374, 375 that engage the conductor members 352,353 and are used to advance the electrodes 356, 357 into the stomachwall by pushing the inner tube 372 while holding the anchor 340 in placewith the push tube 371. The prongs 374, 375 comprise electricallyconductive wires that extend within the insulative material of the innertube 372 to a stimulator/sensor circuit located externally of thepatient's body. The stimulator/sensor may be used to deliver teststimulation pulses to the stomach wall through the electrodes 356, 357or to measure the impedance of the stomach wall tissue between theelectrodes 356, 357. (e.g. to determine sufficient response tostimulation, sense electrical activity). The stimulation response may bedetermined by observing through the endoscope, contractions of thestomach wall, or by determining contractions using one or more sensors,e.g. as described with respect to the various embodiments herein.

After the anchor 340 is in place, an inflation medium is suppliedthrough the inflation tube 373 to inflate the expandable member 348adjacent the outside 100 a of the stomach wall. The inflation tube 373has a thin walled region at its distal end where it joins the inflationlumen 351. After the expandable member 348 is inflated, the inflationtube is removed by twisting or pulling the tube to break it away fromthe anchor 340. The push tube 374 serves to hold the anchor 340 intoplace in the stomach wall as the inflation tube 373 is disengaged. Thebumper ring 366 is then advanced distally to engage the inner wall ofthe stomach with ratchets 365 engaging ratchets 368 to prevent furtherdistal movement of the anchor through the stomach wall. After the anchor340 is in place, the push tube 371 may be removed by unthreading the end371 a on the push tube 371 from the threaded end 372 a of the anchor340. A stimulator unit such as the main body portion 20 described hereinis coupled to the anchor 340 in a manner similar to that describedherein with reference to anchor 123 with electrical contacts 354, 355coupled to the electronics unit within the stimulator through electricalcontacts 362, 363. Electrical contacts 362, 363 are to be coupled to astimulator unit in as similar manner as are contacts 28, 28 a, or 28 bdescribed herein.

Alternatively the laterally extending conductive members 352, 353 may beused to secure the anchor to the stomach wall without requiring anadditional expandable distal portion.

Referring to FIGS. 31A and 31B an alternative stimulator 380 isillustrated comprising a main body portion 382 and an anchor 383. Theanchor 383 includes an expandable distal end 385 for securing the anchorto the stomach wall, seals 398 for sealing the anchor electricalcontacts 394, 395 and electrical contacts 396, 397 of the housing fromthe acidic environment of the stomach. A notch 384 in the anchor isarranged to engage a latch 399 in the main body 382 to couple the anchor383 and the main body 382 together so that contacts 396, 397 of thehousing 382 are in electrical contact with anchor contacts 394, 395,respectively. The anchor 383 further comprises insulated flexibleconductors 386, 387 extending from the anchor 383. The conductors 386,387 are coupled to electrode anchors 388, 389 that are constructed andattached to the stomach wall in a manner similar to the anchors 324, 325described herein with reference to FIGS. 28A and 28B.

FIG. 32 illustrates an alternative embodiment of an anchor device of thepresent invention. Anchor 410 comprises a screw connector 411 located onthe distal end 413 of the anchor 410. The screw 411 includes electrode416 coupled by way of a conductor extending through the anchor 410 toelectrical contact 418. The distal portion of the screw may include aretaining element 419 to prevent dislodgement of the screw from thestomach wall. The anchor 410 includes a notch 414 for engaging a latchin a stimulator unit similar to the main body 20 described herein, sothat the electrical contact 418 is in electrical contact with astimulator unit electrical contact similar to contact 28, 28 a, or 28 bof a main body 20 described herein. An endoscopic instrument engages theproximal end 412 of the anchor 410 and rotates the anchor 410 so that itis secured to a stomach wall.

FIGS. 33A and 33B illustrate an alternative embodiment of an anchor ofthe present invention. Anchor 420 comprises an elongate body 421 havinga proximal portion 422 and a distal portion 423. Anchor also includes anotch 424 and electrical contact 428 located on the elongate body 421.The notch 424 is arranged to couple the anchor to a stimulator unit suchas main body 20 described herein so that the electrical contact 428 isin electrical communication with an electrical contact on the housingsuch as contacts 28, 28 a, or 28 b, described herein. Anchor 420 alsocomprises a clip 425 consisting of prongs 425 a and 425 b, preferablyconstructed of titanium with an insulative coating. An exposed electrodearea 426 is located on prong 425 a. The prong 425 a is coupled by way ofelectrical conductor 429 to electrical contact. The prongs 425 a, 425 bare coupled to lever arms 430 a, 430 b that rotate about spring loadedhinge 432 so that the prongs 425 a, 425 b tend towards a closed positionas illustrated in FIG. 33B. Wires 431 a, 431 b (or strings) are attachedto the lever arms 430 a, 430 b respectively. Wires 431 a, 431 b are alsoattached to an actuating wire 433 that extends through the proximalportion 422 of the anchor 420 where it is attached to a handle 434. Thehandle 434 may be retracted in a proximal direction to pull on the leverarms 430 a, 430 b to open the clip 425 as illustrated in FIG. 33A. Whenthe handle 434 is released, the spring load clip 425 tends to close asshown in FIG. 33B so that the prongs 425 a, 425 b are secured within thestomach wall. As shown in FIG. 33A an endoscopic instrument 436comprising a push tube 437 and a grasper 438 is used to attach the clip425 to the stomach wall. The push tube 437 engages the proximal portion422 of the anchor 420 to advance the anchor to a site for attaching theanchor to the stomach wall. A grasper 438 extends through the push tubeand includes a grasping end effector 439 having grasping arms 439 a and439 b that rotate about hinge 440 which is coupled to an actuatingdevice extending through the push tube 437 out of the patient's mouth.The grasping arms are used to grasp the handle 434 of the anchor and thegrasper 438 is retracted from the push tube 437 to pull the handle toopen the clip, as illustrated in FIG. 33A. The clip 425 is advanced tothe site on the stomach wall for attachment. The handle 434 is thenreleased so that the prongs 425 a and 425 b engage the stomach wall withelectrode 426 in electrical contact with the wall. A stimulator unit maythen be attached to the anchor in a manner similar to the attachment ofanchor 123 and main body 20 described herein.

Referring now to FIGS. 34A and 34B an alternative device is illustratedfor attachment to the wall of the stomach or other organ. The device 450comprises an electronics unit 455 located in a main body portion 451.The device further comprises an attachment device 454 for attaching themain body portion 451 to the inside 100 b of the stomach wall 100. Theattachment device 454 comprises a clip 465 consisting of prongs 465 aand 465 b. The prongs 465 a and 465 b include one or more sensors ortherapeutic devices located thereon. Preferably, the sensor ortherapeutic devices comprises electrodes 466 and 467 located on prongs465 a, and 465 b respectively. The prongs 465 a and 465 b are preferablyconstructed of titanium with an insulative coating. The prongs 465 a 465b are coupled by way of electrical conductors 469 a, 469 b respectivelyto electronics unit 455. The prongs 465 a, 465 b are coupled to leverarms 470 a, 470 b that rotate about spring loaded hinge 472 so that theprongs 465 a, 465 b tend towards a closed position illustrated in FIG.34B. Wires 471 a, 471 b (or strings) are attached to the lever arms 470a, 470 b respectively. Wires 471 a and 471 b are also attached to anactuating wire 473 that extends through the proximal portion 462 of thedevice 450 where it is attached to a handle 474. The handle 474 may beretracted in a proximal direction to pull on the lever arms 470 a, 470 bto open the clip 465 as illustrated in FIG. 34A. When the handle 474 isreleased, the spring load clip 465 tends to close as shown in FIG. 34Bso that the prongs 465 a, 465 b are secured within the stomach wall. Anendoscopic instrument may be used to place the device 450 or to removethe device, by manipulating the handle 474.

The electronics unit 455 comprises an electromagnetic coil 456 forinductively receiving power from an external source. The electromagneticcoil 456 is coupled to a voltage regulating circuit 457, which iscoupled to electrodes 466, 467. The voltage regulating circuit 457operates to convert a high frequency AC signal to a regulated voltagesignal that acts as a stimulation burst delivered to the stomach wallthrough electrodes 466, 467. Stimulation pulses in accordance with astimulation program may be supplied to the electrodes 466, 467 which mayact as electrically opposite bipolar electrodes. A plurality of devices450 may be placed in various locations in the stomach wall. Preferablyeach device has electronics operating at a frequency different from theother devices or operating at the same frequency but responding todigital commands that are different for each device, so that thestimulation program may selectively stimulate various locations in thestomach. Additionally or alternatively, the devices 450 may act assensors sensing electrical characteristics of the stomach wall. Also,other passive sensors may be located on the device. The sensors maysense a parameter of the stomach wall and transmit a representativesignal to an external device via the electromagnetic coil when promptedby an external power signal.

Referring to FIGS. 35A and 35B, an endoscopic instrument 480 is used tomap electrical activity in the stomach wall and to identify andcharacterize the response of the stomach wall to various electricalstimulation parameters. The instrument 480 comprises an elongateflexible member 481 generally formed of a coil 482 with a lumen 483extending therethrough. An end effector 484 is located at the distal endof the instrument 480. The end effector 484 comprises electrode members486, 487 coupled together by a hinge 485. The electrode members 486, 487include electrodes 488, 489 located at the ends of the members 486, 487.The electrodes 488, 489 are coupled through conductors 490, 491extending through electrode members 486, 487 to wires 492, 493 whichextend through the lumen 483 in the instrument 480 to a proximallylocated handle 499. The wires 492, 493 are coupled to an externalstimulator/recorder unit 498, which supplies stimulation energy toelectrodes 488, 489 through wires 492, 493 and records electricalactivity sensed by the electrodes through the wires 492, 493. Amechanical wire 494 is coupled to a hinge actuating device 495 andextends through the lumen 483 to handle 499. The electrode members 486,487 are initially in a closed position. When the wire 494 is moveddistally using handle 499, the hinge actuating device 495 rotates theelectrode members 486, 487 about hinge 485 to spread the electrodemembers 486, 487 and electrodes 488, 489 apart from each other. In thisposition (FIG. 35B), the electrodes may be placed on the stomach wall ata desired site to measure and record electrical activity, electricalparameters, or to provide electrical stimulation pulses to the stomachwall. Upon providing stimulation pulses to the stomach wall, theresponse of the stomach (e.g., the presence, absence or degree ofcontraction) may be observed, either visually or through a sensor (notshown) located on the end effector 484 that senses muscle contractions,such as, for example, a strain gauge. The ideal location for attaching astimulation device may be determined by sensing electrical activity,electrical parameters or by observing a location where stimulationresults in a desired response. Also the ideal stimulation parameters orprogram may also be determined with the device by observing the responseof a site to various stimulation parameters delivered by the endeffector 484.

The materials of the attachment devices, stimulators and housings of thepresent invention are preferably selected for long-term use in thestomach, i.e., two or more years. Suitable materials include thematerials described herein, such as those described with respect to theconstruction of the main body 20.

The invention has been described with reference to preferred embodimentsand in particular to a gastric stimulator, the present inventioncontemplates that the attachment devices may be used to attach a numberof functional devices to the wall of the stomach for sensing parametersof the stomach or its environment, or for diagnosing or providingtreatment to the stomach. The attachment device may incorporate suchsensing, diagnostic or treatment devices within the attachment device.Such functional devices may also be separately attached to the stomachand/or to the attachment device or to another functional device. Theattachment device or functional devices may communicate to an externalrecorder or controller by way of telemetry. They may be battery poweredor powered by inductive coupling. A plurality of functional devices maybe attached to the stomach wall. The functional devices may beprogrammed to respond to information or signals delivered by otherfunctional devices whether the signals are delivered from one device toanother through conductors or whether the signals are delivered, e.g.through the stomach wall or medium within the stomach.

It is also contemplated that instruments described herein to attach orremove the attachment devices and stimulators may be used to attach andremove a variety of functional devices or to perform a number ofdifferent endoscopic procedures. Alternative mechanisms for attachingthe various elements to the stomach wall are also contemplated,including for example staples, sutures and other means.

While the invention has been described with reference to preferredembodiment, it will be understood that variations and modifications maybe made within the scope of the following claims. Such modifications mayinclude substituting elements or components which perform substantiallythe same function in substantially the same way to achieve substantiallythe same result that the invention can be practiced with modificationwithin the scope of the following claims.

1. An attachment device for attaching an implantable functional deviceto a stomach wall, wherein the functional device performs a diagnosticor therapeutic function at a stomach from within a body of the patient,the attachment device comprising: a securing device operative to securethe attachment device to the stomach wall, said securing devicecomprising a first portion at least a portion of which is arranged toextend into and through the stomach wall when said attachment device isattached to the stomach wall; a coupling device arranged to receive andcouple the functional device to the attachment device; an expandabledistal portion coupled to said first portion; a second portion coupledto said first portion, said expandable distal portion and second portionarranged to secure the attachment device to the stomach wall byrestrainingly engaging an inner stomach wall surface and an outerstomach wall surface; and an electrode disposed along the first portionbetween the expandable portion and the second portion so as toelectrically couple the electrode to the stomach wall.
 2. The attachmentdevice of claim 1 wherein said second portion comprises a bumperarranged to engage said first portion of the attachment device so thatsaid bumper abuts the inner surface of the stomach wall.
 3. Theattachment device of claim 1 wherein said expandable distal portioncomprises a spring mechanism biased in an expanded position.
 4. Theattachment device of claim 1 wherein said expandable distal portioncomprises an inflatable member.
 5. The attachment device of claim 4further comprising: an inflation lumen in fluid communication with saidinflatable member and an inflation medium for inflating said inflatablemember.
 6. The attachment device of claim 4 wherein said inflationmedium comprises a curable polymer.
 7. An attachment device forattaching an implantable functional device to a stomach wall, whereinthe functional device performs a diagnostic or therapeutic function at astomach from within a body of the patient, the attachment devicecomprising: a securing device operative to secure the attachment deviceto the stomach wall, said securing device comprising a first portion atleast a portion of which is arranged to extend into and through thestomach wall when said attachment device is attached to the stomachwall; and a distal portion and a proximal portion disposed along thefirst portion, wherein when said attachment device is deployed and saidfirst portion extends through said stomach wall the distal portion andthe proximal portion engage an outer surface of the stomach wall and aninner surface of the stomach wall; an electrode disposed along an outersurface of the first portion between the distal portion and the proximalportion so as to electrically couple the functional device to thestomach wall; and a coupling device arranged to receive and couple thefunctional device to the attachment device.
 8. The attachment device ofclaim 7 wherein said distal portion comprises an expandable member. 9.The system of claim 1 wherein said securing device comprises a screw.10. An attachment means for attaching an implantable functional means toa stomach wall, the functional means comprising signal generation meansand a power source configured for implantation into the patient, theattachment means comprising: a securing means for securing theattachment means to the stomach wall; and a coupling means for receivingand coupling said functional means to said attachment means so as tomechanically support the functional means on the wall of the stomachafter the attachment means has been secured to the stomach wall.
 11. Theattachment means of claim 10 further comprising a releasable latch meansfor latching and unlatching said coupling means from a coupledengagement with a device attached to said attachment means.
 12. Theattachment means of claim 10 further comprising a release means forreleasing said attachment means from engagement with a stomach wall. 13.The attachment means of claim 10 wherein said securing means is arrangedto secure said attachment means in a substantially perpendicularorientation with respect to the natural orientation of the stomach wall.14. The attachment means of claim 10 further comprising an expandablemeans for securing said attachment means to the stomach wall.
 15. Theattachment means of claim 14 wherein said expandable means comprises aninflatable means for sealingly securing said expandable means adjacentan outer surface of the stomach wall.
 16. The attachment means of claim10 further comprising a bumper means for engaging the attachment meansso that said bumper means abuts an inner surface of the stomach wall.17. The attachment device of claim 1 further comprising: a functionaldevice configured to perform a diagnostic or therapeutic function at thestomach.
 18. The attachment device of claim 17 wherein the functionaldevice comprises electronic circuitry configured to supply anelectrically stimulating signal to a stomach wall through an electrode.19. The attachment device of claim 18 wherein the functional devicefurther comprises an electrode coupled to the electronic circuitry andconfigured to be electrically coupled to the stomach wall.